Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modern wind turbine typically includes a tower, a generator, a gearbox, a nacelle, and a rotor. The rotor typically includes a rotatable hub having one or more rotor blades attached thereto. A pitch bearing is configured operably between the hub and the rotor blade to allow for rotation of the rotor blade about a pitch axis. The rotor blades capture kinetic energy of wind using known airfoil principles. The rotor blades transmit the kinetic energy in the form of rotational energy so as to turn a shaft coupling the rotor blades to a gearbox, or if a gearbox is not used, directly to the generator. The generator then converts the mechanical energy to electrical energy that may be deployed to a utility grid.
During operation, a pitch bearing may become worn causing one or more of the rotor blades to move from a desired pitch setting. The normal operational pitch range of the rotor blades is generally far less than the complete circumferential range of the bearing and, in the event of a worn sector of the bearing, the bearing can be indexed to a new sector relative to the pitch drive gear/motor. This procedure is typically carried out by removing and lowering the rotor blade, indexing the pitch bearing so to engage a new set of pitch bearing teeth, and raising and re-attaching the rotor blade. Current systems and methods for removing rotor blades utilize large, specialized cranes because the cranes must have load capacity to lower the blade from the hub to the ground and then back up to the height of the hub. Such cranes are costly to use, lease, and/or maintain, and often require dedicated road construction simply to bring the crane to the wind turbine site.
Thus, an improved system and method for re-indexing a pitch bearing of a wind turbine would be advantageous. For example, a system and method for re-indexing a pitch bearing of a wind turbine wherein the rotor blade need not be lowered to the ground would be desired in the art.